Would you feel different if Dr. Minsky was one of your readers, or Dr. Lenat, Dennett, etc?
I am not picking on you, because I think you are making an important decision here, but I think you are drawing a line between those that read the articles on the site and those that might publish articles elsewhere.
If so, then the criterion I mentioned before would be logical: only allow links to articles published elsewhere.
Personally I don't want to read self advertisement, product plugs, lunacy, or pseudo-religious nonsense. Given free-rein, that is what would be published on the front page along with the items of quality. On the other hand, I would be very happy to see anything based in science and logic, whether or not it has been published elsewhere, or is a "mainstream" conformant piece.
That takes discernment on your part. If it aint science, don't print it.
I don't see alternatives other than either doing the screening yourself, or letting other publishers do it.
If you are looking for a consensus opinion on what to do, then you have my vote of confidence to screen out the nonsense.